Publications
2018 |
Chant, R. J.; Sommerfield, C. K.; Talke, S. A. Impact of Channel Deepening on Tidal and Gravitational Circulation in a Highly Engineered Estuarine Basin Journal Article In: Estuaries and Coasts, 2018, ISSN: 1559-2731. @article{Chant2018, title = {Impact of Channel Deepening on Tidal and Gravitational Circulation in a Highly Engineered Estuarine Basin}, author = {R. J. Chant and C. K. Sommerfield and S. A. Talke}, url = {https://doi.org/10.1007/s12237-018-0379-6}, doi = {10.1007/s12237-018-0379-6}, issn = {1559-2731}, year = {2018}, date = {2018-03-07}, journal = {Estuaries and Coasts}, abstract = {Deepening of estuarine channels is a common practice to ensure navigation. Here, we investigate whether such deepening impacts physical processes such as the strength of the estuarine exchange flow, the horizontal salinity gradient, and tidal dynamics. We analyze recent and historical hydrodynamic observations in Newark Bay, New Jersey, to assess the effect of channel deepening on tides, circulation, and salinity. The Bay's navigational channel has undergone significant deepening, from 3 to 10 m in the nineteenth century to textasciitilde16 m today. Observations presented here include sea-level data from the nineteenth, twentieth, and twenty-first century, and moored Doppler current data and bottom salinity measurements made over the past 20 years. Results show a doubling of the estuarine exchange flow, a slight increase in salinity and in the horizontal salinity gradient, a decrease in tidal current amplitude, and a spatially variable change in the tidal range. The doubling of the exchange flow is consistent with the Hansen and Rattray scaling provided that the horizontal salinity gradient is unable to fully adjust landward because the dredging is limited to a short reach of the estuary. However, uncertainty in channel depth leaves open the possibility that the exchange flow is also augmented by an increase in the horizontal salinity gradient and/or a reduction in vertical mixing. Nevertheless, results demonstrate that a relatively small (15%) increase in depth appears to have doubled the exchange flow. We believe that this result is relevant to other systems where dredging is limited to a short reach of an estuary.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Deepening of estuarine channels is a common practice to ensure navigation. Here, we investigate whether such deepening impacts physical processes such as the strength of the estuarine exchange flow, the horizontal salinity gradient, and tidal dynamics. We analyze recent and historical hydrodynamic observations in Newark Bay, New Jersey, to assess the effect of channel deepening on tides, circulation, and salinity. The Bay's navigational channel has undergone significant deepening, from 3 to 10 m in the nineteenth century to textasciitilde16 m today. Observations presented here include sea-level data from the nineteenth, twentieth, and twenty-first century, and moored Doppler current data and bottom salinity measurements made over the past 20 years. Results show a doubling of the estuarine exchange flow, a slight increase in salinity and in the horizontal salinity gradient, a decrease in tidal current amplitude, and a spatially variable change in the tidal range. The doubling of the exchange flow is consistent with the Hansen and Rattray scaling provided that the horizontal salinity gradient is unable to fully adjust landward because the dredging is limited to a short reach of the estuary. However, uncertainty in channel depth leaves open the possibility that the exchange flow is also augmented by an increase in the horizontal salinity gradient and/or a reduction in vertical mixing. Nevertheless, results demonstrate that a relatively small (15%) increase in depth appears to have doubled the exchange flow. We believe that this result is relevant to other systems where dredging is limited to a short reach of an estuary. |
2017 |
Devlin, A.; Jay, D. A.; Talke, S. A.; Zaron, E. D.; Pan, J.; Lin, H. Coupling of sea level and tidal range changes, with implications for future water levels Journal Article In: Scientific Reports, 7 , 2017. @article{articleb, title = {Coupling of sea level and tidal range changes, with implications for future water levels}, author = {A. Devlin and D. A. Jay and S. A. Talke and E. D. Zaron and J. Pan and H. Lin}, url = {https://www.nature.com/articles/s41598-017-17056-z}, doi = {10.1038/s41598-017-17056-z}, year = {2017}, date = {2017-12-05}, booktitle = {Scientific Reports}, journal = {Scientific Reports}, volume = {7}, abstract = {Are perturbations to ocean tides correlated with changing sea-level and climate, and how will this affect high water levels? Here, we survey 152 tide gauges in the Pacific Ocean and South China Sea and statistically evaluate how the sum of the four largest tidal constituents, a proxy for the highest astronomical tide (HAT), changes over seasonal and interannual time scales. We find that the variability in HAT is significantly correlated with sea-level variability; approximately 35% of stations exhibit a greater than ±50 mm tidal change per meter sea-level fluctuation. Focusing on a subset of three stations with long records, probability density function (PDF) analyses of the 95% percentile exceedance of total sea level (TSL) show long-term changes of this high-water metric. At Hong Kong, the increase in tides significantly amplifies the risk caused by sea-level rise. Regions of tidal decrease and/or amplification highlight the non-linear response to sea-level variations, with the potential to amplify or mitigate against the increased flood risk caused by sea-level rise. Overall, our analysis suggests that in many regions, local flood level determinations should consider the joint effects of non-stationary tides and mean sea level (MSL) at multiple time scales.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Are perturbations to ocean tides correlated with changing sea-level and climate, and how will this affect high water levels? Here, we survey 152 tide gauges in the Pacific Ocean and South China Sea and statistically evaluate how the sum of the four largest tidal constituents, a proxy for the highest astronomical tide (HAT), changes over seasonal and interannual time scales. We find that the variability in HAT is significantly correlated with sea-level variability; approximately 35% of stations exhibit a greater than ±50 mm tidal change per meter sea-level fluctuation. Focusing on a subset of three stations with long records, probability density function (PDF) analyses of the 95% percentile exceedance of total sea level (TSL) show long-term changes of this high-water metric. At Hong Kong, the increase in tides significantly amplifies the risk caused by sea-level rise. Regions of tidal decrease and/or amplification highlight the non-linear response to sea-level variations, with the potential to amplify or mitigate against the increased flood risk caused by sea-level rise. Overall, our analysis suggests that in many regions, local flood level determinations should consider the joint effects of non-stationary tides and mean sea level (MSL) at multiple time scales. |
Devlin, A. T.; Jay, D. A.; Zaron, E. D.; Talke, S. A.; Pan, J.; Lin, H. Tidal Variability Related to Sea Level Variability in the Pacific Ocean Journal Article In: Journal of Geophysical Research: Oceans, pp. n/a–n/a, 2017, ISSN: 2169-9291. @article{JGRC:JGRC22519, title = {Tidal Variability Related to Sea Level Variability in the Pacific Ocean}, author = {A. T. Devlin and D. A. Jay and E. D. Zaron and S. A. Talke and J. Pan and H. Lin}, url = {http://dx.doi.org/10.1002/2017JC013165}, doi = {10.1002/2017JC013165}, issn = {2169-9291}, year = {2017}, date = {2017-09-30}, journal = {Journal of Geophysical Research: Oceans}, pages = {n/a--n/a}, abstract = {Ocean tides are changing worldwide for reasons unrelated to astronomical forcing. Changes in tidal properties coupled with altered mean sea level (MSL) may yield higher peak water levels and increased occurrence of short-term exceedance events such as storm surge and nuisance flooding. Here we investigate the hypothesis that changes in relative sea-level are correlated with alterations in tidal amplitudes. Our approach focuses on the correlation between short-term (monthly to interannual) fluctuations in sea-level with changes in tidal properties of major ocean tides (M2, and K1; S2 and O1) at 152 gauges. Results suggest that sea-level variability is correlated to inter-annual tidal variability at most (92%) of tide gauges in the Pacific, with statistically significant rates between ±10 and ±500 mm per meter sea-level rise observed. These tidal anomalies, while influenced by basin-scale climate processes and sea-level changes, appear to be locally forced (in part) and not coherent over amphidromic or basin-wide scales. Overall, the Western Pacific shows a greater concentration of tide/sea level correlations at interannual time scales than the Eastern Pacific; 44% and 46% of gauges are significant in K1 and O1 in the west compared to 29% and 30% in the east, and 63% and 53% of gauges in the west are significant in M2 and S2 versus 47% and 32% in the east. Seasonal variation in tidal properties is less apparent in the empirical record, with statistically significant seasonal variations observed at only 35% of all gauges, with the largest concentrations in Southeast Asia.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Ocean tides are changing worldwide for reasons unrelated to astronomical forcing. Changes in tidal properties coupled with altered mean sea level (MSL) may yield higher peak water levels and increased occurrence of short-term exceedance events such as storm surge and nuisance flooding. Here we investigate the hypothesis that changes in relative sea-level are correlated with alterations in tidal amplitudes. Our approach focuses on the correlation between short-term (monthly to interannual) fluctuations in sea-level with changes in tidal properties of major ocean tides (M2, and K1; S2 and O1) at 152 gauges. Results suggest that sea-level variability is correlated to inter-annual tidal variability at most (92%) of tide gauges in the Pacific, with statistically significant rates between ±10 and ±500 mm per meter sea-level rise observed. These tidal anomalies, while influenced by basin-scale climate processes and sea-level changes, appear to be locally forced (in part) and not coherent over amphidromic or basin-wide scales. Overall, the Western Pacific shows a greater concentration of tide/sea level correlations at interannual time scales than the Eastern Pacific; 44% and 46% of gauges are significant in K1 and O1 in the west compared to 29% and 30% in the east, and 63% and 53% of gauges in the west are significant in M2 and S2 versus 47% and 32% in the east. Seasonal variation in tidal properties is less apparent in the empirical record, with statistically significant seasonal variations observed at only 35% of all gauges, with the largest concentrations in Southeast Asia. |
Al-Murib, M.; Wells, S.; Talke, S. A. Estimation of Surface Water Temperature of the Tigris River System in Iraq Book Chapter In: World Environmental and Water Resources Congress 2017, 2017. @inbook{doi:10.1061/9780784480632.016, title = {Estimation of Surface Water Temperature of the Tigris River System in Iraq}, author = {M. Al-Murib and S. Wells and S. A. Talke}, url = {http://ascelibrary.org/doi/abs/10.1061/9780784480632.016}, doi = {10.1061/9780784480632.016}, year = {2017}, date = {2017-05-01}, booktitle = {World Environmental and Water Resources Congress 2017}, abstract = {Monitoring surface water temperatures (Tw) in lakes, rivers, and reservoirs is a key component of environmental management and influences water quality by affecting bio-geo chemical reaction rates, altering the saturation concentration of dissolved oxygen (DO), and influencing the susceptibility of fish to disease. Temperatures in the Tigris River, one of the largest rivers in the Middle East, are influenced by factors such as heat fluxes at the air-water and human activities such as direct discharge of water to the river. However, modeling and management of water temperature is limited by a paucity of in-situ data, which prevents calibration of models. In this study, we infill data gaps by estimating Tw using the thermal bands of both the Landsat 5 TM and Landsat 7 ETM+ sensors. These satellite-based estimates, typically measured once or twice a month with 60-120m resolution, are then used to develop a regression model that relates daily water temperature to daily air temperature and river flow. These estimates are used to define the Tw boundary conditions for a hydrodynamic and water quality model of the Tigris River based on a 2D implementation of the CE-QUAL-W2 (W2) numerical model. Initial results suggest that there is a significant agreement between modeled and remotely estimated data of Tw. Results suggest that short-wave solar radiation is the most important factor that controls seasonal Tw variations. However, anthropogenic influence is observed as a result of return irrigation flows and flows from Tharthar Lake.}, keywords = {}, pubstate = {published}, tppubtype = {inbook} } Monitoring surface water temperatures (Tw) in lakes, rivers, and reservoirs is a key component of environmental management and influences water quality by affecting bio-geo chemical reaction rates, altering the saturation concentration of dissolved oxygen (DO), and influencing the susceptibility of fish to disease. Temperatures in the Tigris River, one of the largest rivers in the Middle East, are influenced by factors such as heat fluxes at the air-water and human activities such as direct discharge of water to the river. However, modeling and management of water temperature is limited by a paucity of in-situ data, which prevents calibration of models. In this study, we infill data gaps by estimating Tw using the thermal bands of both the Landsat 5 TM and Landsat 7 ETM+ sensors. These satellite-based estimates, typically measured once or twice a month with 60-120m resolution, are then used to develop a regression model that relates daily water temperature to daily air temperature and river flow. These estimates are used to define the Tw boundary conditions for a hydrodynamic and water quality model of the Tigris River based on a 2D implementation of the CE-QUAL-W2 (W2) numerical model. Initial results suggest that there is a significant agreement between modeled and remotely estimated data of Tw. Results suggest that short-wave solar radiation is the most important factor that controls seasonal Tw variations. However, anthropogenic influence is observed as a result of return irrigation flows and flows from Tharthar Lake. |
Hudson, A. S.; Talke, S. A.; Jay, D. A. Using Satellite Observations to Characterize the Response of Estuarine Turbidity Maxima to External Forcing Journal Article In: Estuaries and Coasts, 40 (2), pp. 343–358, 2017, ISSN: 1559-2731. @article{Hudson2017, title = {Using Satellite Observations to Characterize the Response of Estuarine Turbidity Maxima to External Forcing}, author = {A. S. Hudson and S. A. Talke and D. A. Jay}, url = {https://doi.org/10.1007/s12237-016-0164-3}, doi = {10.1007/s12237-016-0164-3}, issn = {1559-2731}, year = {2017}, date = {2017-03-01}, journal = {Estuaries and Coasts}, volume = {40}, number = {2}, pages = {343--358}, abstract = {This study explores the spatial and temporal character of turbidity maxima in the Columbia River Estuary (CRE) using satellite observations. Surface reflectance data measured by the Moderate Imaging Spectroradiometer (MODIS) were calibrated against in situ measurements of surface turbidity (R 2 = 0.85 for 205 measurements). More than 1500 satellite images from 2000 to 2015 were then conditionally sampled to explore the physical processes that drive the spatial distribution of the turbidity field. We find satellite measurements are able to describe seasonal, spring--neap, and spatial features of the estuarine turbidity maxima (ETM) that are not easily observable by other means. System-wide levels of turbidity are most sensitive to river flow and spring--neap tidal range, with a weaker correlation to wind and waves. Maximum surface turbidity is observed in winter during elevated flow from coastal tributaries and remains elevated during the spring freshet of the main stem Columbia. Two ETM with asymmetric along-channel profiles are observed, one in the North Channel and another in the South Channel. Turbidity distributions migrate downstream as tidal range and river flow increase but appear to become topographically trapped near topographic holes at river kilometers 15--20. Hence, depth-sensitive circulation processes like internal asymmetry and gravitational circulation are likely important mechanisms for trapping particles and determining ETM location. These conclusions confirm the theoretical result that along-channel distributions of turbidity should have an asymmetric distribution and emphasize the role of bottom topography.}, keywords = {}, pubstate = {published}, tppubtype = {article} } This study explores the spatial and temporal character of turbidity maxima in the Columbia River Estuary (CRE) using satellite observations. Surface reflectance data measured by the Moderate Imaging Spectroradiometer (MODIS) were calibrated against in situ measurements of surface turbidity (R 2 = 0.85 for 205 measurements). More than 1500 satellite images from 2000 to 2015 were then conditionally sampled to explore the physical processes that drive the spatial distribution of the turbidity field. We find satellite measurements are able to describe seasonal, spring--neap, and spatial features of the estuarine turbidity maxima (ETM) that are not easily observable by other means. System-wide levels of turbidity are most sensitive to river flow and spring--neap tidal range, with a weaker correlation to wind and waves. Maximum surface turbidity is observed in winter during elevated flow from coastal tributaries and remains elevated during the spring freshet of the main stem Columbia. Two ETM with asymmetric along-channel profiles are observed, one in the North Channel and another in the South Channel. Turbidity distributions migrate downstream as tidal range and river flow increase but appear to become topographically trapped near topographic holes at river kilometers 15--20. Hence, depth-sensitive circulation processes like internal asymmetry and gravitational circulation are likely important mechanisms for trapping particles and determining ETM location. These conclusions confirm the theoretical result that along-channel distributions of turbidity should have an asymmetric distribution and emphasize the role of bottom topography. |
Arns, A.; Dangendorf, S.; Jensen, J.; Talke, S. A.; Bender, J.; Pattiaratchi, C. Sea-level rise induced amplification of coastal protection design heights Journal Article In: Scientific Reports, 7 , 2017. @article{article, title = {Sea-level rise induced amplification of coastal protection design heights}, author = {A. Arns and S. Dangendorf and J. Jensen and S. A. Talke and J. Bender and C. Pattiaratchi}, url = {https://www.nature.com/articles/srep40171}, doi = {10.1038/srep40171}, year = {2017}, date = {2017-01-06}, booktitle = {Scientific Reports}, journal = {Scientific Reports}, volume = {7}, abstract = {Coastal protection design heights typically consider the superimposed effects of tides, surges, waves, and relative sea-level rise (SLR), neglecting non-linear feedbacks between these forcing factors. Here, we use hydrodynamic modelling and multivariate statistics to show that shallow coastal areas are extremely sensitive to changing non-linear interactions between individual components caused by SLR. As sea-level increases, the depth-limitation of waves relaxes, resulting in waves with larger periods, greater amplitudes, and higher run-up; moreover, depth and frictional changes affect tide, surge, and wave characteristics, altering the relative importance of other risk factors. Consequently, sea-level driven changes in wave characteristics, and to a lesser extent, tides, amplify the resulting design heights by an average of 48–56%, relative to design changes caused by SLR alone. Since many of the world’s most vulnerable coastlines are impacted by depth-limited waves, our results suggest that the overall influence of SLR may be greatly underestimated in many regions.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Coastal protection design heights typically consider the superimposed effects of tides, surges, waves, and relative sea-level rise (SLR), neglecting non-linear feedbacks between these forcing factors. Here, we use hydrodynamic modelling and multivariate statistics to show that shallow coastal areas are extremely sensitive to changing non-linear interactions between individual components caused by SLR. As sea-level increases, the depth-limitation of waves relaxes, resulting in waves with larger periods, greater amplitudes, and higher run-up; moreover, depth and frictional changes affect tide, surge, and wave characteristics, altering the relative importance of other risk factors. Consequently, sea-level driven changes in wave characteristics, and to a lesser extent, tides, amplify the resulting design heights by an average of 48–56%, relative to design changes caused by SLR alone. Since many of the world’s most vulnerable coastlines are impacted by depth-limited waves, our results suggest that the overall influence of SLR may be greatly underestimated in many regions. |
Zaron, E. D.; Ray, R. D. Using an altimeter-derived internal tide model to remove tides from in situ data Journal Article In: Geophysical Research Letters, 44 (9), pp. 4241–4245, 2017, ISSN: 1944-8007, (2017GL072950). @article{GRL:GRL55764, title = {Using an altimeter-derived internal tide model to remove tides from in situ data}, author = {E. D. Zaron and R. D. Ray}, url = {http://dx.doi.org/10.1002/2017GL072950}, doi = {10.1002/2017GL072950}, issn = {1944-8007}, year = {2017}, date = {2017-01-01}, journal = {Geophysical Research Letters}, volume = {44}, number = {9}, pages = {4241--4245}, abstract = {Internal waves at tidal frequencies, i.e., the internal tides, are a prominent source of variability in the ocean associated with significant vertical isopycnal displacements and currents. Because the isopycnal displacements are caused by ageostrophic dynamics, they contribute uncertainty to geostrophic transport inferred from vertical profiles in the ocean. Here it is demonstrated that a newly developed model of the main semidiurnal (M2) internal tide derived from satellite altimetry may be used to partially remove the tide from vertical profile data, as measured by the reduction of steric height variance inferred from the profiles. It is further demonstrated that the internal tide model can account for a component of the near-surface velocity as measured by drogued drifters. These comparisons represent a validation of the internal tide model using independent data and highlight its potential use in removing internal tide signals from in situ observations.}, note = {2017GL072950}, keywords = {}, pubstate = {published}, tppubtype = {article} } Internal waves at tidal frequencies, i.e., the internal tides, are a prominent source of variability in the ocean associated with significant vertical isopycnal displacements and currents. Because the isopycnal displacements are caused by ageostrophic dynamics, they contribute uncertainty to geostrophic transport inferred from vertical profiles in the ocean. Here it is demonstrated that a newly developed model of the main semidiurnal (M2) internal tide derived from satellite altimetry may be used to partially remove the tide from vertical profile data, as measured by the reduction of steric height variance inferred from the profiles. It is further demonstrated that the internal tide model can account for a component of the near-surface velocity as measured by drogued drifters. These comparisons represent a validation of the internal tide model using independent data and highlight its potential use in removing internal tide signals from in situ observations. |
Hudson, A. S.; Talke, S. A.; Branch, R.; Chickadel, C.; Farquharson, G.; Jessup, A. Remote Measurements of Tides and River Slope Using an Airborne Lidar Instrument Journal Article In: Journal of Atmospheric and Oceanic Technology, 34 (4), pp. 897-904, 2017. @article{doi:10.1175/JTECH-D-16-0197.1, title = {Remote Measurements of Tides and River Slope Using an Airborne Lidar Instrument}, author = {A. S. Hudson and S. A. Talke and R. Branch and C. Chickadel and G. Farquharson and A. Jessup}, url = {https://doi.org/10.1175/JTECH-D-16-0197.1}, doi = {10.1175/JTECH-D-16-0197.1}, year = {2017}, date = {2017-01-01}, journal = {Journal of Atmospheric and Oceanic Technology}, volume = {34}, number = {4}, pages = {897-904}, abstract = {AbstractTides and river slope are fundamental characteristics of estuaries, but they are usually undersampled due to deficiencies in the spatial coverage of water level measurements. This study aims to address this issue by investigating the use of airborne lidar measurements to study tidal statistics and river slope in the Columbia River estuary. Eight plane transects over a 12-h period yield at least eight independent measurements of water level at 2.5-km increments over a 65-km stretch of the estuary. These data are fit to a sinusoidal curve and the results are compared to seven in situ gauges. In situ– and lidar-based tide curves agree to within a root-mean-square error of 0.21 m, and the lidar-based river slope estimate of 1.8 × 10−5 agrees well with the in situ–based estimate of 1.4 × 10−5 (4 mm km−1 difference). Lidar-based amplitude and phase estimates are within 10% and 8°, respectively, of their in situ counterparts throughout most of the estuary. Error analysis suggests that increased measurement accuracy and more transects are required to reduce the errors in estimates of tidal amplitude and phase. However, the results validate the use of airborne remote sensing to measure tides and suggest this approach can be used to systematically study water levels at a spatial density not possible with in situ gauges.}, keywords = {}, pubstate = {published}, tppubtype = {article} } AbstractTides and river slope are fundamental characteristics of estuaries, but they are usually undersampled due to deficiencies in the spatial coverage of water level measurements. This study aims to address this issue by investigating the use of airborne lidar measurements to study tidal statistics and river slope in the Columbia River estuary. Eight plane transects over a 12-h period yield at least eight independent measurements of water level at 2.5-km increments over a 65-km stretch of the estuary. These data are fit to a sinusoidal curve and the results are compared to seven in situ gauges. In situ– and lidar-based tide curves agree to within a root-mean-square error of 0.21 m, and the lidar-based river slope estimate of 1.8 × 10−5 agrees well with the in situ–based estimate of 1.4 × 10−5 (4 mm km−1 difference). Lidar-based amplitude and phase estimates are within 10% and 8°, respectively, of their in situ counterparts throughout most of the estuary. Error analysis suggests that increased measurement accuracy and more transects are required to reduce the errors in estimates of tidal amplitude and phase. However, the results validate the use of airborne remote sensing to measure tides and suggest this approach can be used to systematically study water levels at a spatial density not possible with in situ gauges. |
Kemp, A. C.; Hill, T. D.; Vane, C. H.; Cahill, N.; Orton, P. M.; Talke, S. A.; Parnell, A. C.; Sanborn, K.; Hartig, E. K. Relative sea-level trends in New York City during the past 1500 years Journal Article In: The Holocene, 27 (8), pp. 1169-1186, 2017. @article{doi:10.1177/0959683616683263, title = {Relative sea-level trends in New York City during the past 1500 years}, author = {A. C. Kemp and T. D. Hill and C. H. Vane and N. Cahill and P. M. Orton and S. A. Talke and A. C. Parnell and K. Sanborn and E. K. Hartig}, url = {https://doi.org/10.1177/0959683616683263}, doi = {10.1177/0959683616683263}, year = {2017}, date = {2017-01-01}, journal = {The Holocene}, volume = {27}, number = {8}, pages = {1169-1186}, abstract = {New York City (NYC) is threatened by 21st-century relative sea-level (RSL) rise because it will experience a trend that exceeds the global mean and has high concentrations of low-lying infrastructure and socioeconomic activity. To provide a long-term context for anticipated trends, we reconstructed RSL change during the past ~1500 years using a core of salt-marsh sediment from Pelham Bay in The Bronx. Foraminifera and bulk-sediment δ13C values were used as sea-level indicators. The history of sediment accumulation was established by radiocarbon dating and recognition of pollution and land-use trends of known age in down-core elemental, isotopic, and pollen profiles. The reconstruction was generated within a Bayesian hierarchical model to accommodate multiple proxies and to provide a unified statistical framework for quantifying uncertainty. We show that RSL in NYC rose by ~1.70 m since ~575 CE (including ~0.38 m since 1850 CE). The rate of RSL rise increased markedly at 1812–1913 CE from ~1.0 to ~2.5 mm/yr, which coincides with other reconstructions along the US Atlantic coast. We investigated the possible influence of tidal-range change in Long Island Sound on our reconstruction using a regional tidal model, and we demonstrate that this effect was likely small. However, future tidal-range change could exacerbate the impacts of RSL rise in communities bordering Long Island Sound. The current rate of RSL rise is the fastest that NYC has experienced for >1500 years, and its ongoing acceleration suggests that projections of 21st-century local RSL rise will be realized.}, keywords = {}, pubstate = {published}, tppubtype = {article} } New York City (NYC) is threatened by 21st-century relative sea-level (RSL) rise because it will experience a trend that exceeds the global mean and has high concentrations of low-lying infrastructure and socioeconomic activity. To provide a long-term context for anticipated trends, we reconstructed RSL change during the past ~1500 years using a core of salt-marsh sediment from Pelham Bay in The Bronx. Foraminifera and bulk-sediment δ13C values were used as sea-level indicators. The history of sediment accumulation was established by radiocarbon dating and recognition of pollution and land-use trends of known age in down-core elemental, isotopic, and pollen profiles. The reconstruction was generated within a Bayesian hierarchical model to accommodate multiple proxies and to provide a unified statistical framework for quantifying uncertainty. We show that RSL in NYC rose by ~1.70 m since ~575 CE (including ~0.38 m since 1850 CE). The rate of RSL rise increased markedly at 1812–1913 CE from ~1.0 to ~2.5 mm/yr, which coincides with other reconstructions along the US Atlantic coast. We investigated the possible influence of tidal-range change in Long Island Sound on our reconstruction using a regional tidal model, and we demonstrate that this effect was likely small. However, future tidal-range change could exacerbate the impacts of RSL rise in communities bordering Long Island Sound. The current rate of RSL rise is the fastest that NYC has experienced for >1500 years, and its ongoing acceleration suggests that projections of 21st-century local RSL rise will be realized. |
2016 |
Thomson, J.; Schwendeman, M. S.; Zippel, S. F.; Moghimi, S.; Gemmrich, J.; Rogers, W. E. Wave-breaking Turbulence in the Ocean Surface Layer Journal Article In: Journal of Physical Oceanography, 46 (6), pp. 1857-1870, 2016. @article{Thomson2016, title = {Wave-breaking Turbulence in the Ocean Surface Layer}, author = {J. Thomson and M. S. Schwendeman and S. F. Zippel and S. Moghimi and J. Gemmrich and W. E. Rogers}, url = {https://journals.ametsoc.org/doi/abs/10.1175/JPO-D-15-0130.1}, doi = {10.1175/JPO-D-15-0130.1}, year = {2016}, date = {2016-06-02}, journal = {Journal of Physical Oceanography}, volume = {46}, number = {6}, pages = {1857-1870}, abstract = {Observations of winds, waves, and turbulence at the ocean surface are compared with several analytic formulations and a numerical model for the input of turbulent kinetic energy by wave breaking and the subsequent dissipation. The observations are generally consistent with all of the formulations, although some differences are notable at winds greater than 15 m s−1. The depth dependence of the turbulent dissipation rate beneath the waves is fit to a decay scale, which is sensitive to the choice of vertical reference frame. In the surface-following reference frame, the strongest turbulence is isolated within a shallow region of depths much less than one significant wave height. In a fixed reference frame, the strong turbulence penetrates to depths that are at least half of the significant wave height. This occurs because the turbulence of individual breakers persists longer than the dominant period of the waves and thus the strong surface turbulence is carried from crest to trough with the wave orbital motion.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Observations of winds, waves, and turbulence at the ocean surface are compared with several analytic formulations and a numerical model for the input of turbulent kinetic energy by wave breaking and the subsequent dissipation. The observations are generally consistent with all of the formulations, although some differences are notable at winds greater than 15 m s−1. The depth dependence of the turbulent dissipation rate beneath the waves is fit to a decay scale, which is sensitive to the choice of vertical reference frame. In the surface-following reference frame, the strongest turbulence is isolated within a shallow region of depths much less than one significant wave height. In a fixed reference frame, the strong turbulence penetrates to depths that are at least half of the significant wave height. This occurs because the turbulence of individual breakers persists longer than the dominant period of the waves and thus the strong surface turbulence is carried from crest to trough with the wave orbital motion. |
Zaron, E. D. On the observability of bottom topography from measurements of tidal sea surface height Journal Article In: Ocean Modelling, 102 , pp. 55-63, 2016. @article{Zaron2016b, title = {On the observability of bottom topography from measurements of tidal sea surface height}, author = {E. D. Zaron}, url = {https://www.sciencedirect.com/science/article/pii/S1463500316300221}, doi = {10.1016/j.ocemod.2016.04.008}, year = {2016}, date = {2016-04-23}, journal = {Ocean Modelling}, volume = {102}, pages = {55-63}, abstract = {The question of whether features of the ocean bottom topography can be identified from measurements of water level is investigated using a simplified one-dimensional barotropic model. Because of the nonlinear dependence of the sea surface height on the water depth, a linearized analysis is performed concerning the identification of a Gaussian bump within two specific depth profiles, (1) a constant depth domain, and, (2) a constant depth domain adjoining a near-resonant continental shelf. Observability is quantified by examining the estimation error in a series of identical-twin experiments varying data density, tide wavelength, assumed (versus actual) topographic correlation scale, and friction. For measurements of sea surface height that resolve the scale of the topographic perturbation, the fractional error in the bottom topography is approximately a factor of 10 larger than the fractional error of the sea surface height. Domain-scale and shelf-scale resonances may lead to inaccurate topography estimates due to a reduction in the effective number of degrees of freedom in the dynamics, and the amplification of nonlinearity. A realizability condition for the variance of the topography error in the limit of zero bottom depth is proposed which is interpreted as a bound on the fractional error of the topography. Appropriately designed spatial covariance models partly ameliorate the negative impact of shelf-scale near-resonance, and highlight the importance of spatial covariance modeling for bottom topography estimation.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The question of whether features of the ocean bottom topography can be identified from measurements of water level is investigated using a simplified one-dimensional barotropic model. Because of the nonlinear dependence of the sea surface height on the water depth, a linearized analysis is performed concerning the identification of a Gaussian bump within two specific depth profiles, (1) a constant depth domain, and, (2) a constant depth domain adjoining a near-resonant continental shelf. Observability is quantified by examining the estimation error in a series of identical-twin experiments varying data density, tide wavelength, assumed (versus actual) topographic correlation scale, and friction. For measurements of sea surface height that resolve the scale of the topographic perturbation, the fractional error in the bottom topography is approximately a factor of 10 larger than the fractional error of the sea surface height. Domain-scale and shelf-scale resonances may lead to inaccurate topography estimates due to a reduction in the effective number of degrees of freedom in the dynamics, and the amplification of nonlinearity. A realizability condition for the variance of the topography error in the limit of zero bottom depth is proposed which is interpreted as a bound on the fractional error of the topography. Appropriately designed spatial covariance models partly ameliorate the negative impact of shelf-scale near-resonance, and highlight the importance of spatial covariance modeling for bottom topography estimation. |
Moftakahri, H. R.; Jay, D. A.; Talke, S. A. Estimating river discharge using multiple-tide gauges distributed along a channel Journal Article In: Journal of Geophysical Research: Oceans, 121 (4), pp. 2078-2097, 2016. @article{Moftakahri2016, title = {Estimating river discharge using multiple-tide gauges distributed along a channel}, author = {H. R. Moftakahri and D. A. Jay and S. A. Talke}, year = {2016}, date = {2016-04-01}, journal = {Journal of Geophysical Research: Oceans}, volume = {121}, number = {4}, pages = {2078-2097}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Zaron, E. D.; deCarvalho, R. Identification and Reduction of Retracker-Related Noise in Altimeter-Derived Sea Surface Height Measurements Journal Article In: Journal of Atmospheric and Oceanic Technology, 33 (1), 2016. @article{Zaron2016, title = {Identification and Reduction of Retracker-Related Noise in Altimeter-Derived Sea Surface Height Measurements}, author = {E. D. Zaron and R. deCarvalho}, year = {2016}, date = {2016-01-29}, journal = {Journal of Atmospheric and Oceanic Technology}, volume = {33}, number = {1}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Moghimi, S.; Ozkan-Haller, H. T.; Wilson, G. W.; Kurapov, A. Data Assimilation for Bathymetry Estimation at a Tidal Inlet Journal Article In: Journal of Atmospheric and Oceanic Technology, 0 (0), 2016. @article{Moghimi2016, title = {Data Assimilation for Bathymetry Estimation at a Tidal Inlet}, author = {S. Moghimi and H. T. Ozkan-Haller and G. W. Wilson and A. Kurapov}, year = {2016}, date = {2016-01-12}, journal = {Journal of Atmospheric and Oceanic Technology}, volume = {0}, number = {0}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Orton, P. M.; Hall, T. M.; Talke, S. A.; Blumberg, A. F.; Georgas, N.; Vinogradov, S. A validated tropical-extratropical flood hazard assessment for New York Harbor Journal Article In: Journal of Geophysical Research: Oceans, 121 (12), pp. 8904–8929, 2016, ISSN: 2169-9291. @article{JGRC:JGRC22000, title = {A validated tropical-extratropical flood hazard assessment for New York Harbor}, author = {P. M. Orton and T. M. Hall and S. A. Talke and A. F. Blumberg and N. Georgas and S. Vinogradov}, url = {http://dx.doi.org/10.1002/2016JC011679}, doi = {10.1002/2016JC011679}, issn = {2169-9291}, year = {2016}, date = {2016-01-01}, journal = {Journal of Geophysical Research: Oceans}, volume = {121}, number = {12}, pages = {8904--8929}, abstract = {Recent studies of flood risk at New York Harbor (NYH) have shown disparate results for the 100 year storm tide, providing an uncertain foundation for the flood mitigation response after Hurricane Sandy. Here we present a flood hazard assessment that improves confidence in our understanding of the region's present-day potential for flooding, by separately including the contribution of tropical cyclones (TCs) and extratropical cyclones (ETCs), and validating our modeling study at multiple stages against historical observations. The TC assessment is based on a climatology of 606 synthetic storms developed from a statistical-stochastic model of North Atlantic TCs. The ETC assessment is based on simulations of historical storms with many random tide scenarios. Synthetic TC landfall rates and the final TC and ETC flood exceedance curves are all shown to be consistent with curves computed using historical data, within 95% confidence ranges. Combining the ETC and TC results together, the 100 year return period storm tide at NYH is 2.70 m (2.51–2.92 at 95% confidence), and Hurricane Sandy's storm tide of 3.38 m was a 260 year (170–420) storm tide. Deeper analyses of historical flood reports from estimated Category-3 hurricanes in 1788 and 1821 lead to new estimates and reduced uncertainties for their floods and show that Sandy's storm tide was the largest at NYH back to at least 1700. The flood exceedance curves for ETCs and TCs have sharply different slopes due to their differing meteorology and frequency, warranting separate treatment in hazard assessments.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Recent studies of flood risk at New York Harbor (NYH) have shown disparate results for the 100 year storm tide, providing an uncertain foundation for the flood mitigation response after Hurricane Sandy. Here we present a flood hazard assessment that improves confidence in our understanding of the region's present-day potential for flooding, by separately including the contribution of tropical cyclones (TCs) and extratropical cyclones (ETCs), and validating our modeling study at multiple stages against historical observations. The TC assessment is based on a climatology of 606 synthetic storms developed from a statistical-stochastic model of North Atlantic TCs. The ETC assessment is based on simulations of historical storms with many random tide scenarios. Synthetic TC landfall rates and the final TC and ETC flood exceedance curves are all shown to be consistent with curves computed using historical data, within 95% confidence ranges. Combining the ETC and TC results together, the 100 year return period storm tide at NYH is 2.70 m (2.51–2.92 at 95% confidence), and Hurricane Sandy's storm tide of 3.38 m was a 260 year (170–420) storm tide. Deeper analyses of historical flood reports from estimated Category-3 hurricanes in 1788 and 1821 lead to new estimates and reduced uncertainties for their floods and show that Sandy's storm tide was the largest at NYH back to at least 1700. The flood exceedance curves for ETCs and TCs have sharply different slopes due to their differing meteorology and frequency, warranting separate treatment in hazard assessments. |
Familkhalili, R.; Talke, S. A. The effect of channel deepening on tides and storm surge: A case study of Wilmington, NC Journal Article In: Geophysical Research Letters, 43 (17), pp. 9138–9147, 2016, ISSN: 1944-8007, (2016GL069494). @article{GRL:GRL54897, title = {The effect of channel deepening on tides and storm surge: A case study of Wilmington, NC}, author = {R. Familkhalili and S. A. Talke}, url = {http://dx.doi.org/10.1002/2016GL069494}, doi = {10.1002/2016GL069494}, issn = {1944-8007}, year = {2016}, date = {2016-01-01}, journal = {Geophysical Research Letters}, volume = {43}, number = {17}, pages = {9138--9147}, abstract = {In this study we investigate the hypothesis that increasing channel depth in estuaries can amplify both tides and storm surge by developing an idealized numerical model representing the 1888, 1975, and 2015 bathymetric conditions of the Cape Fear River Estuary, NC. Archival tide gauge data recovered from the U.S. National Archives indicates that mean tidal range in Wilmington has doubled to 1.55 m since the 1880s, with a much smaller increase of 0.07 m observed near the ocean boundary. These tidal changes are reproduced by simulating channel depths of 7 m (1888 condition) and 15.5 m (modern condition). Similarly, model sensitivity studies using idealized, parametric tropical cyclones suggest that the storm surge in the worst-case, CAT-5 event may have increased from 3.8 ± 0.25 m to 5.6 ± 0.6 m since the nineteenth century. The amplification in both tides and storm surge is influenced by reduced hydraulic drag caused by greater mean depths.}, note = {2016GL069494}, keywords = {}, pubstate = {published}, tppubtype = {article} } In this study we investigate the hypothesis that increasing channel depth in estuaries can amplify both tides and storm surge by developing an idealized numerical model representing the 1888, 1975, and 2015 bathymetric conditions of the Cape Fear River Estuary, NC. Archival tide gauge data recovered from the U.S. National Archives indicates that mean tidal range in Wilmington has doubled to 1.55 m since the 1880s, with a much smaller increase of 0.07 m observed near the ocean boundary. These tidal changes are reproduced by simulating channel depths of 7 m (1888 condition) and 15.5 m (modern condition). Similarly, model sensitivity studies using idealized, parametric tropical cyclones suggest that the storm surge in the worst-case, CAT-5 event may have increased from 3.8 ± 0.25 m to 5.6 ± 0.6 m since the nineteenth century. The amplification in both tides and storm surge is influenced by reduced hydraulic drag caused by greater mean depths. |
Ray, R. D.; Zaron, E. D. M2 Internal Tides and Their Observed Wavenumber Spectra from Satellite Altimetry Journal Article In: Journal of Physical Oceanography, 46 (1), pp. 3-22, 2016. @article{doi:10.1175/JPO-D-15-0065.1, title = {M2 Internal Tides and Their Observed Wavenumber Spectra from Satellite Altimetry}, author = {R. D. Ray and E. D. Zaron}, url = {https://doi.org/10.1175/JPO-D-15-0065.1}, doi = {10.1175/JPO-D-15-0065.1}, year = {2016}, date = {2016-01-01}, journal = {Journal of Physical Oceanography}, volume = {46}, number = {1}, pages = {3-22}, abstract = {AbstractA near-global chart of surface elevations associated with the stationary M2 internal tide is empirically constructed from multimission satellite altimeter data. An advantage of a strictly empirical mapping approach is that results are independent of assumptions about ocean wave dynamics and, in fact, can be used to test such assumptions. A disadvantage is that present-day altimeter coverage is only marginally adequate to support mapping such short-wavelength features. Moreover, predominantly north–south ground-track orientations and contamination from nontidal oceanographic variability can lead to deficiencies in mapped tides. Independent data from Cryosphere Satellite-2 (CryoSat-2) and other altimeters are used to test the solutions and show positive reduction in variance except in regions of large mesoscale variability. The tidal fields are subjected to two-dimensional wavenumber spectral analysis, which allows for the construction of an empirical map of modal wavelengths. Mode-1 wavelengths show good agreement with theoretical wavelengths calculated from the ocean’s mean stratification, with a few localized exceptions (e.g., Tasman Sea). Mode-2 waves are detectable in much of the ocean, with wavelengths in reasonable agreement with theoretical expectations, but their spectral signatures grow too weak to map in some regions.}, keywords = {}, pubstate = {published}, tppubtype = {article} } AbstractA near-global chart of surface elevations associated with the stationary M2 internal tide is empirically constructed from multimission satellite altimeter data. An advantage of a strictly empirical mapping approach is that results are independent of assumptions about ocean wave dynamics and, in fact, can be used to test such assumptions. A disadvantage is that present-day altimeter coverage is only marginally adequate to support mapping such short-wavelength features. Moreover, predominantly north–south ground-track orientations and contamination from nontidal oceanographic variability can lead to deficiencies in mapped tides. Independent data from Cryosphere Satellite-2 (CryoSat-2) and other altimeters are used to test the solutions and show positive reduction in variance except in regions of large mesoscale variability. The tidal fields are subjected to two-dimensional wavenumber spectral analysis, which allows for the construction of an empirical map of modal wavelengths. Mode-1 wavelengths show good agreement with theoretical wavelengths calculated from the ocean’s mean stratification, with a few localized exceptions (e.g., Tasman Sea). Mode-2 waves are detectable in much of the ocean, with wavelengths in reasonable agreement with theoretical expectations, but their spectral signatures grow too weak to map in some regions. |
Jurisa, J. T.; Nash, J. D.; Moum, J. N.; Kilcher, L. F. Controls on Turbulent Mixing in a Strongly Stratified and Sheared Tidal River Plume Journal Article In: Journal of Physical Oceanography, 46 (8), pp. 2373-2388, 2016. @article{doi:10.1175/JPO-D-15-0156.1, title = {Controls on Turbulent Mixing in a Strongly Stratified and Sheared Tidal River Plume}, author = {J. T. Jurisa and J. D. Nash and J. N. Moum and L. F. Kilcher}, url = {https://doi.org/10.1175/JPO-D-15-0156.1}, doi = {10.1175/JPO-D-15-0156.1}, year = {2016}, date = {2016-01-01}, journal = {Journal of Physical Oceanography}, volume = {46}, number = {8}, pages = {2373-2388}, abstract = {AbstractConsiderable effort has been made to parameterize turbulent kinetic energy (TKE) dissipation rate ε and mixing in buoyant plumes and stratified shear flows. Here, a parameterization based on Kunze et al. is examined, which estimates ε as the amount of energy contained in an unstable shear layer (Ri < Ric) that must be dissipated to increase the Richardson number Ri = N2/S2 to a critical value Ric within a turbulent decay time scale. Observations from the tidal Columbia River plume are used to quantitatively assess the relevant parameters controlling ε over a range of tidal and river discharge forcings. Observed ε is found to be characterized by Kunze et al.’s form within a factor of 2, while exhibiting slightly decreased skill near Ri = Ric. Observed dissipation rates are compared to estimates from a constant interfacial drag formulation that neglects the direct effects of stratification. This is found to be appropriate in energetic regimes when the bulk-averaged Richardson number Rib is less than Ric/4. However, when Rib > Ric/4, the effects of stratification must be included. Similarly, ε scaled by the bulk velocity and density differences over the plume displays a clear dependence on Rib, decreasing as Rib approaches Ric. The Kunze et al. ε parameterization is modified to form an expression for the nondimensional dissipation rate that is solely a function of Rib, displaying good agreement with the observations. It is suggested that this formulation is broadly applicable for unstable to marginally unstable stratified shear flows.}, keywords = {}, pubstate = {published}, tppubtype = {article} } AbstractConsiderable effort has been made to parameterize turbulent kinetic energy (TKE) dissipation rate ε and mixing in buoyant plumes and stratified shear flows. Here, a parameterization based on Kunze et al. is examined, which estimates ε as the amount of energy contained in an unstable shear layer (Ri < Ric) that must be dissipated to increase the Richardson number Ri = N2/S2 to a critical value Ric within a turbulent decay time scale. Observations from the tidal Columbia River plume are used to quantitatively assess the relevant parameters controlling ε over a range of tidal and river discharge forcings. Observed ε is found to be characterized by Kunze et al.’s form within a factor of 2, while exhibiting slightly decreased skill near Ri = Ric. Observed dissipation rates are compared to estimates from a constant interfacial drag formulation that neglects the direct effects of stratification. This is found to be appropriate in energetic regimes when the bulk-averaged Richardson number Rib is less than Ric/4. However, when Rib > Ric/4, the effects of stratification must be included. Similarly, ε scaled by the bulk velocity and density differences over the plume displays a clear dependence on Rib, decreasing as Rib approaches Ric. The Kunze et al. ε parameterization is modified to form an expression for the nondimensional dissipation rate that is solely a function of Rib, displaying good agreement with the observations. It is suggested that this formulation is broadly applicable for unstable to marginally unstable stratified shear flows. |
Zaron, E. D. Laser Doppler velocimetry using a modified computer mouse Journal Article In: American Journal of Physics, 84 (10), pp. 810-813, 2016. @article{doi:10.1119/1.4960466, title = {Laser Doppler velocimetry using a modified computer mouse}, author = {E. D. Zaron}, url = {https://doi.org/10.1119/1.4960466}, doi = {10.1119/1.4960466}, year = {2016}, date = {2016-01-01}, journal = {American Journal of Physics}, volume = {84}, number = {10}, pages = {810-813}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Hoitink, A. J. F.; Jay, D. A. Tidal river dynamics: Implications for deltas Journal Article In: Reviews of Geophysics, 54 (1), pp. 240–272, 2016, ISSN: 1944-9208, (2015RG000507). @article{ROG:ROG20097, title = {Tidal river dynamics: Implications for deltas}, author = {A. J. F. Hoitink and D. A. Jay}, url = {http://dx.doi.org/10.1002/2015RG000507}, doi = {10.1002/2015RG000507}, issn = {1944-9208}, year = {2016}, date = {2016-01-01}, journal = {Reviews of Geophysics}, volume = {54}, number = {1}, pages = {240--272}, abstract = {Tidal rivers are a vital and little studied nexus between physical oceanography and hydrology. It is only in the last few decades that substantial research efforts have been focused on the interactions of river discharge with tidal waves and storm surges into regions beyond the limit of salinity intrusion, a realm that can extend inland hundreds of kilometers. One key phenomenon resulting from this interaction is the emergence of large fortnightly tides, which are forced long waves with amplitudes that may increase beyond the point where astronomical tides have become extinct. These can be larger than the linear tide itself at more landward locations, and they greatly influence tidal river water levels and wetland inundation. Exploration of the spectral redistribution and attenuation of tidal energy in rivers has led to new appreciation of a wide range of consequences for fluvial and coastal sedimentology, delta evolution, wetland conservation, and salinity intrusion under the influence of sea level rise and delta subsidence. Modern research aims at unifying traditional harmonic tidal analysis, nonparametric regression techniques, and the existing understanding of tidal hydrodynamics to better predict and model tidal river dynamics both in single-thread channels and in branching channel networks. In this context, this review summarizes results from field observations and modeling studies set in tidal river environments as diverse as the Amazon in Brazil, the Columbia, Fraser and Saint Lawrence in North America, the Yangtze and Pearl in China, and the Berau and Mahakam in Indonesia. A description of state-of-the-art methods for a comprehensive analysis of water levels, wave propagation, discharges, and inundation extent in tidal rivers is provided. Implications for lowland river deltas are also discussed in terms of sedimentary deposits, channel bifurcation, avulsion, and salinity intrusion, addressing contemporary research challenges.}, note = {2015RG000507}, keywords = {}, pubstate = {published}, tppubtype = {article} } Tidal rivers are a vital and little studied nexus between physical oceanography and hydrology. It is only in the last few decades that substantial research efforts have been focused on the interactions of river discharge with tidal waves and storm surges into regions beyond the limit of salinity intrusion, a realm that can extend inland hundreds of kilometers. One key phenomenon resulting from this interaction is the emergence of large fortnightly tides, which are forced long waves with amplitudes that may increase beyond the point where astronomical tides have become extinct. These can be larger than the linear tide itself at more landward locations, and they greatly influence tidal river water levels and wetland inundation. Exploration of the spectral redistribution and attenuation of tidal energy in rivers has led to new appreciation of a wide range of consequences for fluvial and coastal sedimentology, delta evolution, wetland conservation, and salinity intrusion under the influence of sea level rise and delta subsidence. Modern research aims at unifying traditional harmonic tidal analysis, nonparametric regression techniques, and the existing understanding of tidal hydrodynamics to better predict and model tidal river dynamics both in single-thread channels and in branching channel networks. In this context, this review summarizes results from field observations and modeling studies set in tidal river environments as diverse as the Amazon in Brazil, the Columbia, Fraser and Saint Lawrence in North America, the Yangtze and Pearl in China, and the Berau and Mahakam in Indonesia. A description of state-of-the-art methods for a comprehensive analysis of water levels, wave propagation, discharges, and inundation extent in tidal rivers is provided. Implications for lowland river deltas are also discussed in terms of sedimentary deposits, channel bifurcation, avulsion, and salinity intrusion, addressing contemporary research challenges. |